<s>
RTML	B-Application
is	O
a	O
proprietary	O
programming	O
language	O
used	O
exclusively	O
by	O
Yahoo	B-Application
!	I-Application
</s>
<s>
'	O
s	O
Yahoo	B-Application
!	I-Application
</s>
<s>
Store	O
and	O
Yahoo	B-Application
!	I-Application
</s>
<s>
The	O
language	O
originated	O
at	O
Viaweb	B-Application
,	O
a	O
company	O
founded	O
in	O
1995	O
by	O
Paul	O
Graham	O
and	O
Robert	O
T	O
.	O
Morris	O
,	O
as	O
the	O
template	O
language	O
for	O
their	O
e-commerce	O
platform	O
.	O
</s>
<s>
RTML	B-Application
stands	O
for	O
"	O
Robert	O
T	O
.	O
Morris	O
Language	O
"	O
.	O
</s>
<s>
The	O
RTML	B-Application
editor	O
was	O
offered	O
as	O
an	O
option	O
for	O
customers	O
(	O
usually	O
small	O
businesses	O
)	O
who	O
wanted	O
to	O
customize	O
their	O
online	O
stores	O
more	O
than	O
the	O
built-in	O
templates	O
allowed	O
.	O
</s>
<s>
The	O
built-in	O
templates	O
were	O
also	O
written	O
in	O
RTML	B-Application
,	O
and	O
provided	O
the	O
starting	O
point	O
for	O
most	O
people	O
who	O
used	O
the	O
language	O
.	O
</s>
<s>
In	O
1998	O
,	O
Yahoo	B-Application
!	I-Application
</s>
<s>
bought	O
Viaweb	B-Application
for	O
$49.6	O
million	O
and	O
renamed	O
the	O
service	O
Yahoo	B-Application
!	I-Application
</s>
<s>
Yahoo	B-Application
!	I-Application
</s>
<s>
later	O
offered	O
the	O
RTML-based	O
content	B-Protocol
management	I-Protocol
system	I-Protocol
in	O
a	O
hosting	O
platform	O
without	O
a	O
shopping	B-Application
cart	I-Application
,	O
under	O
the	O
name	O
Yahoo	B-Application
!	I-Application
</s>
<s>
In	O
2003	O
,	O
Yahoo	B-Application
!	I-Application
</s>
<s>
renamed	O
the	O
Yahoo	B-Application
!	I-Application
</s>
<s>
Store	O
service	O
Yahoo	B-Application
!	I-Application
</s>
<s>
Merchant	O
Solutions	O
(	O
part	O
of	O
Yahoo	B-Application
!	I-Application
</s>
<s>
Small	O
Business	O
)	O
,	O
and	O
at	O
the	O
same	O
time	O
began	O
offering	O
new	O
customers	O
the	O
choice	O
of	O
a	O
more	O
standard	O
PHP/MySQL	O
web	O
hosting	O
environment	O
instead	O
of	O
the	O
RTML-based	O
Store	O
Editor	O
.	O
</s>
<s>
,	O
many	O
new	O
Yahoo	B-Application
!	I-Application
</s>
<s>
Merchant	O
Solutions	O
sites	O
and	O
legacy	O
Yahoo	B-Application
!	I-Application
</s>
<s>
Stores	O
continue	O
to	O
be	O
built	O
using	O
the	O
Store	O
Editor	O
and	O
RTML	B-Application
.	O
</s>
<s>
Although	O
Yahoo	B-Application
!	I-Application
</s>
<s>
'	O
s	O
documentation	O
does	O
not	O
mention	O
it	O
,	O
RTML	B-Application
is	O
actually	O
implemented	O
on	O
top	O
of	O
a	O
Lisp-based	O
system	O
.	O
</s>
<s>
Instead	O
,	O
keywords	O
are	O
presented	O
as	O
hyperlinks	O
in	O
a	O
browser-based	O
HTML	B-Language
interface	O
.	O
</s>
<s>
Blocks	O
of	O
code	O
can	O
be	O
pushed	O
and	O
popped	O
from	O
a	O
clipboard	O
,	O
using	O
the	O
stack	B-Application
metaphor	I-Application
.	O
</s>
<s>
The	O
editor	O
maintains	O
the	O
code	O
's	O
s-expression	B-Protocol
structure	O
automatically	O
,	O
and	O
visually	O
represents	O
it	O
in	O
the	O
web	O
interface	O
using	O
indentation	O
instead	O
of	O
Lisp	B-Language
's	O
parentheses	O
.	O
</s>
<s>
Most	O
of	O
the	O
keywords	O
correspond	O
to	O
HTML	B-Language
elements	O
,	O
but	O
there	O
are	O
also	O
conditionals	B-Language
,	O
recursion	O
,	O
and	O
other	O
control	O
flow	O
features	O
that	O
make	O
it	O
a	O
"	O
real	O
"	O
programming	O
language	O
.	O
</s>
<s>
RTML	B-Application
templates	O
are	O
evaluated	O
dynamically	O
for	O
each	O
pageview	O
during	O
editing	O
,	O
but	O
for	O
the	O
live	O
site	O
a	O
"	O
publish	O
"	O
process	O
generates	O
static	O
HTML	B-Language
files	I-Language
from	O
them	O
.	O
</s>
<s>
Yahoo	B-Application
!	I-Application
</s>
<s>
'	O
s	O
documentation	O
used	O
to	O
say	O
that	O
RTML	B-Application
was	O
an	O
acronym	O
for	O
"	O
Real	O
Time	O
Markup	O
Language	O
"	O
,	O
but	O
Graham	O
admitted	O
that	O
"	O
we	O
made	O
up	O
various	O
explanations	O
for	O
what	O
RTML	B-Application
was	O
supposed	O
to	O
stand	O
for	O
,	O
but	O
actually	O
I	O
named	O
it	O
after	O
Robert	O
Morris	O
,	O
the	O
other	O
founder	O
of	O
Viaweb	B-Application
,	O
whose	O
username	O
is	O
rtm.	O
"	O
</s>
